Field of Invention
This invention relates to torque/speed transmissions, specifically to a method for reducing the tension in the transmission belts of torque/speed transmissions.
Description of Prior Art
A CVT that has the potential to replace automatic and manual transmissions in vehicles is a CVT 4, which is described in U.S. patent application Ser. Nos. 13/629,613, 13/730,958, and 13/889,049.
A CVT 4, which is shown in FIGS. 1 to 4, has one cone with one torque transmitting member mounted on one shaft/spline that is coupled to another cone with one torque transmitting member mounted on another shaft/spline by a transmission belt.
A CVT 4 is promising design because it can allow for the construction of non-friction dependent CVT's without using ratcheting or reciprocating mechanisms. However, if a CVT 4 is transmitting a large torque, then the tension in the transmission belt of the CVT 4 is also large. And sliding a transmission belt under large tension from small diameter of its cone to a large diameter of its cone will also require a large force.
The intent of this disclosure is to describe a CVT 6 that has two CVT 4's for which the transmission belt tension in one of the CVT 4's can be reduced using a novel and non-obvious approach. An obvious approach to reduce transmission belt tension in one of the CVT 4's is by using regular clutches, this approach makes the transmission ratio changing duration too long for the CVT to be practical (a CVT has a lot more transmission ratios than an manual transmission and as such transmission ratio changing in a CVT occurs much more frequently than in a manual transmission). In addition, using regular clutches also causes considerable energy losses.
An earlier design for a CVT 6 was disclosed in U.S. patent application Ser. Nos. 14/182,306, 14/186,853, and 14/475,492. This application discloses a new adjuster that can be used for CVT 6. Said new adjuster uses an indexing mechanism instead of an adjuster motor. This should reduce the cost of a CVT 6 significantly.
The CVT 6 of this disclosure can significantly: reduce the transmission ratio changing force needed, shock loads that occur during transmission ratio changing, and wear due to transmission ratio changing at a more economical cost. As such the CVT 6 of this disclosure can allow for the construction of a more practical, efficient, and economical toothed CVT that has a better chance succeed commercially.
Other Prior Arts
The following prior art that might also be relevant: U.S. Pat. No. 7,713,153; Issue Date: May 11, 2010; Patentee: Naude.